TJ McIntyre: Body cameras will give a new perspective on policing, as water meter protests show

The cameras are roughly the size of a pack of cigarettes and inconspicuous, but not actually covert: the model used by gardai has a fluorescent green ring visible around the lens while in use. Unlike CCTV, these also record audio.

Advances in technology mean that continuous recording for an entire shift is now possible at a reasonable price. Consequently, these cameras are increasingly common worldwide and are being trialled in other forces such as the Metropolitan Police and the PSNI.

Elsewhere, there has been public notice and discussion of the issues they present. For example, the UK Home Office has had guidance on body-worn cameras since 2007. Here, however, Garda management have rolled out cameras with no publicity and no consultation with the Data Protection Commissioner.

This is disappointing, and suggests that management have already forgotten the lessons which should have been learnt from the illegal recording of phone calls to and from Garda stations.

That aside, should we welcome the use of body cameras?

Cameras can certainly invade privacy and we should be wary of new systems which might lead to even more routine surveillance of the public. But unlike other types of surveillance, body cameras also have an important function in ensuring police accountability.

They can benefit police and the public at the same time: providing evidence of crime, protecting police against false allegations of abuse and deterring police abuses of power. In one California study, body-worn cameras resulted in a 50pc reduction in the use of force by police and a 90pc fall in the number of complaints made against police.

Despite these benefits, the technology also presents challenges. If police can choose when to turn on and off the cameras, then there is the risk that there will be no footage available when we need it to investigate allegations of police wrongdoing.

To ensure accountability it would be best if cameras ran throughout an entire shift - but that approach would present real problems for the privacy rights of police themselves.

For example, a whistleblower might fear that management could trawl through their video to find a pretext for disciplinary action.

In the UK, police have used photography and video recording at demonstrations to create a database of protesters and political activists - despite the fact they had not committed any criminal offence.

This was described as something which could have a "chilling effect on the exercise of lawful rights" and the Garda Siochana will have to take this ruling into account in its handling of these video recordings.

There are further concerns if recording is extended from protests and into day-to-day policing. The US has also seen many cases where video recordings have been released or leaked in a way which humiliates individuals - for example, footage of actress Reese Witherspoon being arrested for drunk driving.

To meet the basic requirements of data protection law, gardai will have to ensure the public are put on notice of their use, that information recorded on the cameras is only kept where necessary for a legitimate purpose, or promptly deleted otherwise.

There will have to be provision for strong controls over viewing of the recordings, including the right of those recorded on camera to access their own footage. In addition, the policies should guarantee the privacy rights of gardai themselves.

The next step should be consultation - with the Data Protection Commissioner and the wider public - followed by a public set of guidelines.

Dr TJ McIntyre is a lecturer in the UCD Sutherland School of Law and chair of Digital Rights Ireland